256 The Hunting JVasps 



the sand retain the consistency which it might 

 have at the start, when first disturbed : the 

 insect's movements are free, it is safe under 

 cover, it can take its time and use its tarsi and 

 mandibles without undue hurry. Going in is a 

 very different matter. The Bembex is ham- 

 pered by her prey, which her legs hold clasped 

 to her body ; and the miner is thus deprived of 

 the free use of her tools. And a still graver cir- 

 cumstance is this : brazen parasites, veritable 

 bandits in ambush, crouch here and there in the 

 neighbourhood of the burrow, spying on the 

 mother Wasp as she makes her laborious en- 

 trance, so that they may rush in and lay their 

 ^^g on the piece of game at the very moment 

 when it is about to disappear down the corridor. 

 If they succeed, the Wasp's nurseling, the son of 

 the house, will perish, starved by its gluttonous 

 fellow-boarders. 



The Bembex seems aware of these dangers 

 and makes arrangements for her entrance to be 

 effected swiftly, without serious obstacles — in 

 short, for the sand blocking the door to yield to 

 a mere push of her head, aided by a brisk sweep 

 of her front tarsi. With this object, the material 

 at the approaches to the home are subjected to 

 a sort of sifting. At leisure moments, under a 

 kindly sun, when the larva has its food and does 

 not need her attentions, the mother rakes the 



